At least eight people have been killed by explosions in the Nigerian capital, Abuja, during celebrations to mark 50 years of independence from Britain.
Police have confirmed that two blasts outside the Ministry of Justice were caused by car bombs, which went off about five minutes apart.
Earlier, the Movement for the Emancipation of the Niger Delta (MEND) threatened to target the festivities.
President Goodluck Jonathan, who was inspecting a guard of honour at the time, called it a "wicked act of desperation by criminals and murderers".
Last year the Nigerian government signed an amnesty agreement with rebels in the Delta, offering cash and the promise of job training for former militants who disarmed.
Oil production has increased since the amnesty came into effect - from about 1.6 million barrels per day to about two million now.
The BBC reports most of MEND's attacks have targeted pipelines and supply terminals in the south.